"This way of tying walls together with iron, instead of making them of that substance and form, that they shall naturally poise themselves upon their buttment, is against the rules of good architecture, not only because iron is corruptible by rust, but because it is fallacious, having unequal veins in the metal, some places of the same bar being three times stronger than others, and yet all sound to appearance." Survey of Salisbury Cathedral in 1668, by Sir C. Wren. For my own part, I think it better work to bind a tower with iron, than to support a false dome by a brick pyramid. NOTE IX. Page 60. PLATE III. In this plate, figures 4, 5, and 6, are glazed windows, but fig. 2 is the open light of a belfry tower, and figures 1 and 3 are in triforia, the latter also occurring filled, on the central tower of Coutances. NOTE X. Page 94. _"Ornaments of the transept towers of Rouen."_ The reader cannot but observe agreeableness, as a mere arrangement of shade, which especially belongs to the "sacred trefoil." I do not think that the element of foliation has been enough insisted upon in its intimate relations with the power of Gothic work. If I were asked what was the most distinctive feature of its perfect style, I should say the Trefoil. It is the very soul of it; and I think the loveliest Gothic is always formed upon simple and bold tracings of it, taking place between the blank lancet arch on the one hand, and the overcharged cinquefoiled arch on the other. NOTE XI. Page 95. "_And levelled cusps of stone._" The plate represents one of the lateral windows of the third story of the Palazzo Foscari. It was drawn from the opposite side of the Grand Canal, and the lines of its traceries are therefore given as they appear in somewhat distant effect. It shows only segments of the characteristic quatrefoils of the central windows. I found by measurement their construction exceedingly simple. Four circles are drawn in contact within the large circle. Two tangential lines are then drawn to each opposite pair, enclosing the four circles in a hollow cross. An inner circle struck through the intersections of the circles by the tangents, truncates the cusps. NOTE XII. Page 124. "_Into vertical equal parts._" Not absolutely so. There are variations partly accidental (or at least compelled by the architect's effort to recover the vertical), between the sides of the stories; and the upper and lower story are taller than the rest. There is, however, an apparent equality between five out of the eight tiers. NOTE XIII. Page 133. "_Never paint a column with vertical lines._"